Meter



W. J. WOHLENBERG.

METER.

APPLICATION FILED NOV.10,1917- RENEWED NOV. 17.1921.

1,401 ,299, Patented Dec. 27, 1921.

6 SHEETS-SHEET I.

W. J. WOHLENBERG.

METER.

APPLICATION FILED NOV. 10, 1917. RENEWED NOV. 17.1921.

1,401,299, Patefited Dec. 27, 1921.

w. J. WOHL ENBEBG.

METER. APPLICATION FILED NOV. 10 1917- RENEWED NOV. 17.192].

1,401,299. Patented Dec. 27, 1921.

6 SHEETS-SHEET 3- IIII/I/III/I/ W. J. WOHLENBERG.

METER.

7 APPLICATION FILEDYNOV. 10. 1917. RENEWED NOV. 17.1921. 1,401,299.

Patented Dec. 27, 1921'.

6 SHEETS-SHEET 4.

W. J. WOHLENBERG.

METER. APPLICATION-FILED NOV. 10, 1917. RENEWED NQV. 17.1921.

1,401,299. I Patented Dec. 27, 1921.

6 SHEETSSHEET 5- J6 go'lg. 6 9 I P W. J. WOHLENBERG.

METERK APPLICATION FILED NOV-10, 1917- RENEWED NOV. 17.1921- 1,401,299.Patented Dec. 27, 1921. 6 $HEET3$HEET 6- LL unit. Ki m qS v m on UNITEDSTATES PATENT OFFICE.

WALTER JACOB WOHIiENBERG, OF NEW HAVEN, CONNECTICUT.

METER.

Application filed November 10, 1917, Serial No.

To all whom it may concern:

Be it known that, I, WALTER JAooB WOHL- ENBERG, a citizen of the UnitedStates, and a resident of New Haven, in the county of New Haven andState of Connecticut, have invented new Improvements in Meters, of whichthe following is a full, clear, and exact description.

- y invention relates to meters for determining the quantities of fluidor' energy flow.

An object of my invention is to have the means of having the fluidsdirection of flow deflected by a displaceable surface whereby thedisplacement of said displaceable surface may be a measure of the rateof flow at given fluid densities. I

A second object of my invention is to have the said deflecting surfacessupported at said point of said system of arms, displaceable in astraight line, whereby said deflecting surfaces will be displaced, byvariations in the rate of flow, in straight line directions.

A third object of my invention is to have the means of having themechanism respond automatically to variations of density of the fluidbeing metered, whereby the indications, rates of registering or recordswill'be accurate measures of the weight flow of the I accomplish theseand other objects of my invention by the structures conventionallydisclosed in the accompanyingdrawings, in which similar characters ofreference denote corresponding parts.

Figures 1, 2, 3, 3 4 and Pare diagrammatic representations of the fluidflow existing in the vicinity of the deflecting surface above mentionedand they are included as an aid to the theoretical discussion disclosingthe principle of operation.

Fig. 5 represents a longitudinal cross section disclosing certainfeatures of the in vention.

Figs. 6 6 and 6 are diagrammatic illustrations used in connection withthe explanation of the suspension mechanism shown in Fig. 5.

' Fig. 6 shows a special distribution of the suspension points 18 ofthis mechanism.

Fig. 7 illustrates the mechanism by means of which the magnitudes of themeasuring displacements are corrected automatically for variations ofthe fluid density.

Specification of Letters Patent.

201,412. Renewed November 17, 1921.

conditions of the measuring displacements are caused to take place.

Fig. 9 represents a special form of the deflecting surface against whichthe fluid motion acts.

Fig. 10 shows how the deflecting surface may be supported betweenrollers instead of by the suspension mechanism disclosed in Fig. 5, andFig. 11 is a cross section showing an assembled view of the principalelements involved in the construction of the meter.

Referring now to Fig. 5, 5 represents the fluid inlet and 7 the outletfrom the otherwise leakage proof meter casing 9. The fluid is guidedfrom 5 into 7 by means of the semicircular tube 6 which has initsstraight portions holes or vents 8 whereby Patented Dec. 27, 1921.

Serial No. 515,971.

the static pressure within the space Q will these are in turn supportedby means ofpins 19 respectively by arms 13, 14 and 15 and 17. These armsare supported by stationary or fixed pins 18. The joints at 18, 19, 20and 21 are all hinged and such that the parts fastened together therebyare free to rotate with respect to each other about the in axes ascenters. It follows that the who e arm system is free, within givenlimits, to oscillate about the pins 18.

f now the arms 13, '14, 15 and 17 are of equal lengths and their pointsof suspension 18 are in parallel lines z-z and z'2' and if furthermorethe links 12 are equal in length to links 16 then points 20 and 21 maybe so located that the points 21 will be c0nstrained to move very nearlyin the straight line m-w. This is more readily seen by reference toFigs. 6 and 6'. Referring first now to F ig. 6, there is represented thearrangement of the arms 13 and 14 as shown in the suspension mechanism.Consider that both of these arms may be turned successively about theirpoints of support 18 through equal angles 6, 6 In each position let thepoint p bisect the line joinmg their extremities. It will in each casefall in the straight line w-w.

' Consider now that the arms 13 and 14 are connected by a link as 16Fig. 6". If under these conditions, the arm 13 is rotated through anangle 6 then the arm 14 will be rotated through an angle 6 6 because,for displacement parallel to ww of the points 19 of the arms thedistance between them increases. Consequently, if the distance is toremain constant, then the point 19 of the lower arm must be displaced agreater amount horizontally. This will operate to cause the mid point p,of the link 16 to be displaced a small amount below the line wm in itsnew position p',. There will, however, be a point p, which is again onthis line in the displaced position p,. This point will move a verysmall amount above the line wac in the early part of the displacement aswill any point p, to the left of 12 It is obvious now that the arms andlink may be chosen of such a length that when properly located a pointwill move virtually away from the line ww.

along the straight line w-w. This elementary system of arms as heredescribed is exactly a Watts straight line motion and was invented byJames Watt.

A still nearer approximation is afforded by the suspension mechanism .ofFig 5 which is diagrammatically disclosed in Fig. 6.

In these figures the solid lines show the mechanisms in the centralposition in which now the arms 14, 12 and 13 and 15, 16 and 17 may bemutually at right angles. It is readily seen that the system of arms141213 is exactly equivalent to the system -15-16 17 turned 180 aboutthe same axis w-w. The linkage system A is connected to the invertedlinkage system B at points 20 by means of link 11 having on it a pin ofsupport at 21.

These points 10 or 20, will be located on the links 16 and 12 of thefundamental elements of the mechanism, as previously explained. Then fora displacement of the systems A and B such that 6 :6 and 6 :0 the onepoint 10 will be displaced above the line a2a2 just as much as the otherwill be displaced below this line. If new the points p are connected bya third link as 11 then the displacement angles 6, and 0 can not bequite equal respectively to 6' and 6, and consequently a point 21located on 11 as p, was located on 16 and 12 will move slightly However,just as the displacement of'p from w-w is but a small fractional part ofthat of-the points 19, just so that of 21 will be but a small fractionalpart of that of p, and consequently the variation from the straight linemotion may be reduced to a negligibly small amount. If a still closerapproximation is desired then it is obvious that the points 21- of twoinverted combination systems as described might be connected to a commonlink and on it would be a point having a motion departlows that themechanical friction to such a motion can be reduced to a negligibleamount by making the arms of said suspension mechanism'of such lengthsthat the motion in the joint is very small.

vAs shown in Fig. 5 the rod 10 has a collar 23 against which the spring24 presses. The tension in this spring may be adjusted by means oftension screw 26 having at its end the collar 25 supporting the otherend of said spring.

The tube are 6 has preferably very thin walls so that its inside area isvery nearly equal to that of the pipe ends 5 and 7. For such a conditionthere will be practically constant velocity and uniform flow of thefluid over the path shown. The tubular arc will be perfectly balanced asto static pressure and the only force F existing will be due to thevelocity of the fluid, or rather due to the deflection from the straightline direction which is caused in its motion by the curved path imposed.by the are. This force will cause the arc to be displaced to the leftcompressing the spring 24 and the displacements may be transmitted to ashaft 30 rotated by means of lever 29 which has slot 28 into which thepin 27 fits and hence causes the rotation of said lever when the rod 10is displaced.

These displacements will for a given resistance be governed by the forceF which is proportional to the product 7V The volume of the elementwillbe equal to 'rdB- (11' if its depth is unity and its mass will then beequal to rd0dr-6 where 8 represents the fluid density and g theacceleration due to gravity. It follows constant on a circular arc ofthat the radialforce dF exerted by the particle because of itscurvilinear motion will be equal to grda gg v da 3 The component of thisforce in a direction 02-03 will obviously be equal to tween limits 6 and6 dF,= (sin sin 9 5 57 5. 5

Now for ideal conditions of flow the further assumption may be made that.zV for obviously with zero friction and zero pressure change thiscondition will result. Substituting this condition and multiplying by gwhere n represents the number of such arcs of elementary radial depth,there results,

in which the product 'n d 7' is exactly a the radial depth of the sectori j is Land is exactly 8 the mean density of this sector. It followsthat for this flow as described the force F exerted by a sector z j is Zwill, be exactly equal to sin 0 2; v a e We have now to find therelation between the mean density 8 in the tube are and that in thestraight portion of the pipe.

Referring to Fig. 3 there is represented a section of a tube in whichnow the fluid is at rest. We will consider some of the particles mfalling on the concentric arcs continued into parallel lines. Obviouslynow all of the particles in the tube will fall on some one of such linesand a given are section z" y" is Z will contain a given number of suchparticles or molecules. Consider now that each line of particlespossesses a uniform linear velocity V as shown in Fig. 3 Obviously -nowin the curved partofthe tube these lines of particles will V cos 0d0 (4)To find the total force F x the circular arcs of fluid as 1, 2, n of agiven are of fluid i j is Z of Fig. 2 it is merely necessary to sum upthe forces of the arcs of elementary radial depth. Consider this fluidarc to be divided intoarc sectors each of elementary depth (ll' and thatthe density of arc Z isx of 2, B etcu-to 8 Then obviously any arcsectors as 3 for instance will exert the force exerted by all of (1F(sin 0; sin eg gvga and the arc sectors n will exert the force (11 7 F nn j is Z will exert the dF (sin 6 sin 0 Whence the total sectors 71force become closer together near the outer surface and farther apartnear the inner surface and a small element as (a) will have acting on itthe centrifugal force 03F and a force aZF in the opposite direction dueto the inward rate of variation of pressure. For steady flow theseforces will be such that pressure existing in the fluid.

Now obviously for ideal conditions of flow each line of these particleswill maintain its uniform velocity V about the curve and although theradial space distribution of the successive lines varies there willstill be the same number of total lines passing through the sector z' j70', Z as there are through the sector 2" j is Z wherein the fluid is atrest. Furthermore, the resultant forces aZF and dF atany point'of anyline are exactly at right angles to the direction of the line and forideal flow there is at no point on any line a force between theparticles in the direction of the line. Consequently in any given linethere is no tendency to alter the distances between the particles onthat line although the distances between neighboring particles in thedirection of the line may be altered by one line of particles so tospeak tending to telescope with a line which in the stationaryconditional number of particles occupy the space i j" n Z! on theCHI-V6, as an equal Spac i 3'1. 1' cut out of the straight portion w1llcontain, provided that the cross-sectional areas are equal and that thevolume cut out in the curved section is a sector as c y is" Z"containing the whole cross sectional area of flow. In other words thesame total mass and weight is contained in each volume so cut outwhence.

F,= (sin o sin 0,)A-%V26 7 where A has been substituted for the productZ. r which is obviously the cross sectional area.

Consider now a condition of imperfect flow in which the velocity V mayundergo a considerable variation. Referring to Fig. 4 u represents astraight section of pipe through which the fluid is flowing with avelocity V. If while the fluid is flowing this pipe be bent into theform of an are as shown bymm; .of Fig. 4, then possibly both thevelocity V and thedensity 8 willbe a variable in an arc line. Thetendency will obviously be to'crowd more particles into the circular arethan existed in the straight pipe length. The mean density would therebybe increased and the mean velocity decreased.

These variations would operate to changethe magnitude of F in op ositesenses but since this force varies as 2 and only di rectly as 6 itfollows that the actual force would be, due tosuch imperfections,somewhat smaller than the force F above arrived at. For good conditionsof flow this variation will however be very small and negligible.

Equation now may be expressed as F =KV B (8) ments of rod 10 and lever29 may directly indicate the weight flow of fluid, for, with 8 constanttherewillbe only one value of V6 for each value of the product V 8. If,however, 6 is not constant, that is if the pressure much fluid isflowing as in the other.

and temperature of the fluid vary during the flow, then the magnitude ofV 8 will not be a conclusive indication of the magnitude V8 for theflow. In other words for this condition there may be any number ofvalues V8 for a given product V 6. For instance I; if V22 and 8:4. We

have V 3=16 and 73:8 and II; if V24 and 5:1 then 7 8216 but V5=4.

Now obviously both conditions I and II will cause the same displacementto the above mechanism but in the one case only half as t is necessarytherefore to take account of the fluid density when this varies duringthe flow. This is accomplished as follows:

In Fig. 7 the rod l0is represented as transmitting its displacementthrough pin 27 to lever 31. In the slot of this lever the bar 34 isadapted to slide and its longitudinal position Within the slot iscontrolled by the diaphragm 42. This diaphra functions exactly as thediaphragm 31 in ig. 1 of my application for fluid meters Serial Number198,895. It is a fluid density responsive mechanism and may, as such, bereplaced by the other forms of density responsive mechanisms describedin said application. As in the former invention, the diaphragm orenvelop surrounding the density cell 43 is surrounded by the fluid beingmetered, and the density fluid contained within the cell may be of thesame kind as that being metered, so that at all times the volume 43 willbe directly proportional to the specific volume of the surround ingfluid and inversely proportional to the density of the said surroundingfluid. It

follows that the displacements of the wall 41 means of coupling 48 andthe ratio of magnitudes of longitudinal displacements of 33 to those-of41 maybe adjusted by changing the pin 39 to other holes 37 provided forthe purpose. v

The point 33 now is in the shown arrangement at all times exactly thefulcrum about which the lever 31 is displaced by means of rod 10, sothat the arm length Z, will be inversely proportional to the fluiddensity surrounding 42.

To the other end of the sliding bar 34, at 35,'is pinned the rod 44which may transmit the displacements of the point '35 through lever 46and axle 47 to the outside, if so desired.

Suppose now' that the rod 10 causes a dis- The displacements of theplacement AS of the pin 27, the displacement system to axle 47 which mayproject through of pin 35 caused thereby will obviously be equal to i Asgf Now 1 is proportional to where 5 is the fluid density and if thedisplacement of rod 10 is caused from a deflecting flow are as 6 of Fig.5 then AS, cc V 6 whence 12 AS, =V 6 1 Z V a But Z is practicallyconstant for small displacements AS, whence for such, the displacementsAS will be proportional to the quantity Obviously for each value of-[V8] there is only one value V6 whence the displacements AS will be anexact measure of the rate of weight flow'of the fluid. They-will beproportional to the squares of the weight flow of the fluid.

As shown in this system the fulcrum is between the power and resistingconnections of the levers. This however is not necessary for the sameresult will be attained if for instance the fulcrum 33 were interchangedwith the resisting connection 35 of the link or if the power andresisting connections were interchanged. The relation in which thedisplacements AS of the resisting connection are proportional to (V8)?will be true as long as the sliding bar or link is provided with thefulcrum and either the resisting or power connections, said remainingconnection being'provided on the member 31 or guide.

These displacements may, as before shown. be transmitted through alinkage e casing. In a speclal 'caseit might be desired to have the workof displacement of the force F instead of being stored in a spring as 24be stored in a gravity mechanism as shown in Fig. 8. The rod 10 has aroller 54 pressing against the arm 55 of the pendulum suspended from 56and having at its other end the Weight 57 held in place by the nut 58.If now the rod 10 is displaced an amount a as shown then the pendulumwill be. displaced to the right. The following equation willbe true,

in which F represents the force with which the roller 54 presseshorizontally to the left on the pendulum arm in displacing the pendulum.W represents the weight of the pendulum, a the horizontal distance whichthe center of gravity of the pendulum system is from its point ofsupport 56 and h the vertical distance between the line of action of Fand the point of support 56. For small angles 6 a will be proportionalto s whence where S represents the horizontal distance of thedisplacement of the roller 54 from the position it has when in contactwith the pendulum arm when the latter hangs vertically. The densitymechanism may be applied as before. This arrangement will beparticularly advantageous where the resisting mechanism is to be exposedto high temperatures in that its accuracy will not be affected by such.high temperatures whereas a spring will lose its temper under suchconditions.

Fig. 9 shows a special arrangement of the deflecting surface. In thisarrangement t are the surfaces causing the fluid to assume a curvedpath. The fluid enters through inlet "5 having a definite velocity V.The deflecting tube 6' has a constant total cross sectional area,perpendicular to the direction of flow, at all parts and hence withinthis tube 6'. This condition may be attained by means of an equalizingpipe as 8'. After leavin 6 the fluids velocity Wlll be d1ssipated andthe kinetic. energy of flow w1ll be returned to the fluid at thepressure existing in Q. The fluid temperature will thereby be raised andwe have from the source region Q, for the velocity V in 5 to the chamberQ' exactly a free expansion of the fluid dur ng which its heat. contentremains constant. The density fluid of the density correcting mechanismnow should for accuracy obviously be exposed to the pressure andtemperature conditions of the fluid flowing 1n the passage 5'. This canbe accomplished by providing a chamber as Q" with an opening as 8" to 5.The density chamber and compensatin cylinder may then be located withinthis 0 amber. For all ordinary "rates of flow, however, there will bevery small difbe located in either. The advantage of this arrangement isthat it reduces the necessary has in it the curved elements 72tangential to the direction of flow at entrance and then curving-asshown so that fluid motion will cause a force F to be exerted on 73. Thesuspending linkage is as shown suspended and connected by pins 77 and76, so that the' links 75 may freely rotateabout pins 77 as centers..The element 71 may thus bendis placed across the fluid path againstsmall frictional resistance, and if the arms 75 are of sufficient lengththe relatively small displacements will be virtually in the line w-w.The displacements of. the element 71 are caused to store energy in aconservative resisting medium such as the spring 111 by means of collari110 fixed to rod 73. The other end of the spring is supported againstthe pedestal 112 which is shown bolted to the pressure casing and havinopening 113 through which the rod 73 is ree to move.

This displacement of the flow deflecting element is as before,transmitted to a lever 79 containing a slot 80 inwhich the bar 81slides. The position of this bar is controlled by the density responsivediaphragm 42. In-

stead of a rod 36 with holes 37 as in Fig. 7, this is now shown as aslotted bar 84 in whose slot 85 the block 87 is adapted to slide,

so that the position of the fulcrum at 87 may be controlled from theoutside by means of bolt head 108 on screw bar 104:. This screw bar isfixed longitudinally by means of collars 106 and turns in the threadedbase of the diaphragm mechanism at points 103. As the head 108 is turnedthe diaphragm is moved horizontally and hence the fulcrum 87 is movedlongitudinally in the slot 85. At 107 packing is provided to preventleakage. Some of the fluid being metered enters the chamber 109 throughthe openings 74 so that at all times the diaphragm 42 is surounded bythe pressure and temperature conditions of the fluid being metered. 1

The pin 82 in the bar 81 is the movable fulcrum ,controlled by thedensity mechamsm about which the lever 79 is displaced by the flowdeflecting element. The. pin- 83 on the bar 81 may have attached alinkage sys-' tem 88-89 for the the displacements A to a wire or'thinrod 93. 91 represents a guiding bearing for the rod which has the wire93 attached or fixed at the end 92.

purpose of transmitting This wire 93 now is held in tension by means ofa weak spring 96, as the only purpose of this spring is to hold saidwire 93 in tension. The wire passes through the meter casing in theholeprovided in plug95 and may be fixed in the head 99 by means of screw100. The head 99 has a threaded stem over which the adjusting collar 97screws whence the distance between the spring holding shoulders on 95and 97 may be adjusted and likewise the initial spring tension may beadjusted.

It follows now that since the wire 93 is continually in tension that itmay be very small and still be strong enough to transmit all forcescausing displacements AS If the wire 93 is very small then the holein-plug 95 through which the wire passes may likewise be very small.Then evenwith a small clearance area about the wire such a small openingwill exist that'the fluid leakage therethrou'gh will be negligible. Thissystem therefore providesa mean of transmitting mechanical displacementsinvolving small forces through a wall between spaces ofdifierent fluidpressures and with small leakage of the fluid from the one space to theother. These displacements may be transmitted from head 99 through rod101 guided in bearing 102 to and indicating registering or recordingmechanism.

It is obvious that many changes other than those shown may be made inthe arrangement and construction of this apparatus without departingfrom the spirit and scope of the invention, and therefore I do not wishto limit my invention to the exact 1. In fluid flow meters, thecombination,

with an element responsive to the flow im pulse of the fluid, of anelement proportionally responsive to variations of the fluids densityand a lever composed of two members movable lengthwise relatively toeach other, said lever being provided with a fulcrum, a resistingconnection and a power connection, one of said members, called the link,

being provided with the fulcrum and one of said connections, the othermember, called the guide, belng provided with the other of saidconnections, said link having its'position relatively to said guidemechanicall controlled by the element responsive to variations of thefluid density, said lever having one end mechanically connected with theelement responsive to the fluid flow impulse, as and for the purpose setforth.

2. In fluidflow meters, the combination,

with an element responsive to the flow impulse of the fluid, of anelement responsive to variations of the fluids density and a levercomposed of a guide and a link movable lengthwise relatively to saidguide, said lever being provided with-a fulcrum a resisting connectionand. a power connection, said link being provided with the fulcrum andone of said connections, said guide being provided with the other ofsaid connections, said link being mechanically connected at the fulcrumwith said element responsive to variations of the fluids density, 'andsaid lever having one end me"hanically connected to the elementresponsive to the flow impulse of the fluid, as and for the purposeshown. I

3. In fluid flow meters, the combination, with an element responsive tothe flow impulse of the fluid, of an element responsive to variations ofthe fluidsfdensity and a lever composed of a guide and a link movablelengthwise relatively to said guide, said lever being provided with afulcrum, a resisting connection and a power connection, said link beingprovided with the fulcrum and one of said connections, said guide .beingprovided with the other of said connections, said link beingmechanically connected at the fulcrum with said element responsive tovariations of the fluids density, said element responsive ,to the flowimpulse comprising a flow deflecting surface mounted in the fluid streamon a carriage displaceable by the flow impulse on said surface, saidcarriage beingconnected so as to mechanically transmit its displacementsto a mechanically COIISGI'VatiX G resisting medium and to one end ofsaid lever, as and for the purpose set forth.

4. In fluid flow meters, the combination, with an element responsive tothe flow impulse of the fluid, of an element responsive to variations ofthe fluids density and a lever composed of a guide and a link movablealengthwise relatively 'to said guide, said lever being provided with afulcrum, a resisting connection and a power connection, said link beingprovided with the fulcrum and one of said connections, said guide beingprovided with the other of said connections, said link beingmechanically connected at the fulcrum with said element responsive tovariations of the fluids density, said element responsive to the flowimpulse comprising a curved flow deflecting surface in the fluid flowpath, said curved deflecting surface being at flow entrance tangentialto the fluid stream, said curved deflecting surface being mounted on acarriage displaceable by the flow impulse on,

said deflecting surface, said carriage being connected so as tomechan'icall transmit its displacements to a mechanically cont servatiyeresisting medium and to one end of saidlever, as and for the purposeshown. 5. In fluid flow meters, the combination,

with an element responsive to the flow im-.

pulse of the fluid, of an element responsive to variations of the fluidsdensity and a lever composed of a guide and a link movable lengthwiserelatively to said guide, said lever being provided with a fulcrum, aresisting connection and a power connection, said link being providedwith the fulcrum and one of said connections, said guide being providedwith the other of said connections, said link being mechanicallyconnected at the fulcrum with said element responsive to variations ofthe fluids density, said element responsive to flow impulse comprising aflow deflecting element in the flow path, said deflecting eleinenthaving curved surfaces which are at flow entrance tangential to thefluid stream, said curved portions terminating in straight portions,said deflecting element forming a channel of constantcross sectionalarea normal to the direction of flow, said deflecting element beingmounted on a carriage displaceable by the flow impulse on saiddeflecting surfaces, said carriage being connected so as to mechanicallytransmit its displacements to a mechanically conservative resistingmedium and to one end of said lever, as and for the purpose set forth.

'6. In fluid flow meters, the combination, withan element responsive tothe flow impulse of the fluid, of an element proportionally responsiveto variations of-the fluids density and a lever composed of a guide anda link movable lengthwise relatively to said guide, said lever beingprovided with a fulcrum, a resisting connection and a power connection,said link being provided with the fulcrum and one of said connections,said element responsive to variations of the fluids density confining aquantity of an elastic fluid-within an envelop adapted to be placed inthe fluid being metered, said envelop beingimpervious to the surroundingand confined fluids but being adapted both to conduct heat readilybetween them and to undergo, becauseof the forces acting on it due tovariations of the surrounding fluids density, relative displacements ofits parts allowing equalization of the internal pressure with theexternal pressure, said envelop having a displaceable part mechanicallyconguide, said lever being provided with a fulcrum, a resistingconnection and a power connection, said link being provided with thefulcrum and one of said connections, said element responsive tovariations of the fluids density confining a quantity of an and confinedfluids but being adaptedboth to conduct heat readily between them and to7 undergo, because of the forces acting on it due to variations of thesurrounding fluids density, relative displacements of its parts allowingequalization of the internal pressure with the external pressure, saidenvelop havin a displaceable part mechanically connecte to the link atthe fulcrum, said element responsive to the flow impulse comprising aflow deflecting surface mounted in the fluid stream on a carriagedisplaceable by the flow impulse on said surface, said carriage beingconnected so as to mechanically transmit its displacements to amechanically conservative resisting medium and to one end of said lever,as and for the purpose set forth.

8. In fluid flow meters, the combination,

with an element res onsive to the flow impulse of the fluid, 0 anelement PIOPOItlOIlally responsive to variations of the fluids densityand a lever composed of a guide and a link movable lengthwise relativelyto said guide, said lever being provided with a fulcrum, a resistingconnection and a power connection, said link being provided with thefulcrum and one of said connections, said element responsive tovariations of the fluids density confining a quantity of an elasticfluid of the same kind as the surrounding fluid within an envelopadapted to be placed in the fluid being metered, said envelop beingimpervious to the surrounding and confined fluids but being adapted bothto conduct heat readily between them and to undergo, because of theforces acting on it due to variations of the surrounding fluids density,relative displacements of its parts allowin equalization of the internalpressure with t e external pressure, said envelop having a displaceablepart mechanically connected to the link at the fulcrum, said leverhaving one end mechanically connected to the element res onsive to theflow im ulse of the fluid, as and for the purpose set orth.

9. In fluid flow meters, the combination, with an element responsive tothe flow impulse of the fluid, of an element proportionally responsiveto variations of the fluids density and a lever composed of. a guide anda link movable lengthwise relatively to said guide, said lever beingprovided with a fulcrum, a resisting connection and a power connection,said link being provided with the fulcrum and one of said connections,said element responsive to variations of the fluids density confining aquantity of an elastic fluid of the same kind as the surrounpling fluidwithin an envelop adapted to be placed in the fluid being metered, saidenvelop being impervious to the surrounding and confined fluids butbeing adapted both to conduct heat readily between them and to undergo,because of the forces acting on it due to variations of the surroundingfluids density, relative displacements of its parts allowingequalization of the internal pressure with the external pressure, saidenvelop having a displaceable part mechanically connected to the link atthe fulcrum, said element responsive to the flow impulse comprising aflow deflecting surface mounted in the fluid stream on a carriagedisplaceable by the flow impulse on said surface, said carriage beingconnected so as to mechanically transmit its displacements to amechanically conservative resisting medium and to one 2nd lpf saidlever, as and for the purpose set ort 10. In the fluid flow path ofmeters, a flowplacements to a mechanically conservative resistingmedium.

12. In the fluid 'flow path of meters, a curved flow deflecting surface,said curved deflecting surface being at flow entrance tangential to thefluid stream, said curved portion terminating in a straight portion,said curved deflecting surface being mounted on a carriage displaceableby the flow impulse on said deflecting surface, said carriage beingconnected so as to mechanically transmit its displacements to amechanically conservative resisting medium.

13. In the fluid flow path of meters, a flow deflecting element, salddeflecting element having curved surfaces which are at flow entrancetangential to the fluid stream, said curved portions terminating instraight portions, said deflecting element forming a channel of constantcross sectional area normal to the direction of flow, said deflectingelement being mounted on a carriage displaceable by the flow impulse onsaid deflecting surfaces, said carriage being connected so as tomechanically transmit its displacements to a mechanically conservativeresisting medium.

14. In meters, the combination with a fluid flows, of'a flow deflectingsurface in chamber to and from which the metered the path of theinflowing fluid, said deflecting surface beingmou'n'ted on a carriagedisplaceable by the flow impulse on the deflecting surface, saidcarriage being connected so as to mechanically transmit itsdisplacements to a mechanically conservative resisting medium, theconduit surrounding said fluid stream Within said chamber having anopening in the surface tangential to the flow lines, as and for thepurpose set forth.

15. In meters, the combination with a chamber, having inlet and outletpassages for the metered fluid, of a flow deflecting channel in the pathof-the inflowing fluid, said inlet and outlet passages being of the samecross sectional area, said deflecting channel being at all sections ofsubstantially the same area as the inlet and outlet passages to thechamber, and being curved from tangency with the inlet passageinto theoutlet passage, said deflecting channel being mounted on a carriagedisplaceable by the flow impulse and reaction on said channel, saidcarriage being connected so as to mechanically transmit itsdisplacements to a me chanically conservative resisting medium, theconduit surrounding said fluid stream within said chamber having anopening in the surface tangential to the flow lines, as and for thepurpose set forth.

\VALTER J ACOB WOHLENBERG.

